Within sports, there are numerous styles of performing some action, whether it's how to swing a golf club, shooting a basketball or how to best run a race for example. There is usually no universally preferred style, and even if there were one, people's individual style would vary greatly person to person. How a person performs an action can be influenced by body build, level of fitness, experience, previous coaching, and even cultural impacts. Furthermore, even if an individual has a style to which they aspire, an individual has limited resources to ascertain how their own way of performing an action compares. Professional athletes may have coaches and trainers that can provide detailed guidance. In some cases, the athletes have access to laboratories where their form can be analyzed in a controlled environment. However, most people and even many professionals do not have access to such resources all the time. Such problems of performance styles and lack of access to guidance are evident in other sports and activities as well. Thus, there is a need in the activity monitoring field to create a new and useful system and method for using performance signatures. This invention provides such a new and useful system and method.